In recent years, many measurement devices, such as liquid chromatographs, perform not only measuring operations but also various kinds of data-processing operations using the data obtained from the measuring operations. Usually, a data-processing operation includes multiple tasks, e.g. peak integration, sample identification, calibration, quantitative determination, and statistical calculation, using a data-processing system that is built in or externally connected to the measurement device.
In many cases, the data-processing system for measurement devices consists of a computer on which a specific application program is running. An example of such application programs is disclosed in Non-Patent Document 1 described later.
During its operation, the data-processing system may encounter an abnormality or trouble that prevents the ongoing process from producing a correct result. If the data processing is performed on a step-by-step basis, a failure in one step also prevents the subsequent steps from producing correct results. In a conventional data-processing system, when a problem occurs in a certain step, the system displays a specific character (e.g. the digit “0”) or a blank in each of the areas for showing the results of the aforementioned step and the subsequent steps, indicating that the system has failed to produce correct results.
FIG. 4 shows an example of a quantitative determination report containing some errors, produced by a conventional data-processing system. It shows that the concentration of Methyl_paraben of ID number 1 is zero, which contradicts the fact that the area and height of the peak are 175,519 and 30,759, respectively. This contradiction suggests that some problem has occurred in the analytical curve and/or the quantitative determination parameters used in the method used For Ethyl_paraben of ID number 2, the report indicates the retention time, the area and other values are zero. This result suggests that the chromatogram itself is incorrect or the peak integration method and/or the compound table has some problems.    [Non-Patent Document 1] “GCsolution Software/The Future Standard for Increased GC Productivity and Easy Operation”, [online], Shimadzu Corporation, [Search Date: Nov. 13, 2006], Internet <http://www.ssi.shimadzu.com/products/product.cfm?product=gcsolution>
As shown in FIG. 4, if the report enumerates the results of a sequence of data-processing tasks on the same screen, the user can identify the step in which an error has occurred and make an estimation of the cause of the error.
In contrast, when the result of only one task is displayed on the screen, it is impossible to identify the step in which the error has occurred. For example, suppose that the system has obtained the results shown in FIG. 4 and is now showing only the value “0” of the “Area” for ID number 2. In this situation, the user can tell that some error has occurred but cannot immediately identify the step in which the error has taken place. Therefore, it is necessary to take the trouble of manually browsing through the results of the previous steps one after another.
In a measurement using a liquid chromatograph, it is common to continue the measurement for a long time while automatically exchanging a large number of samples one after another and performing a regular set of data-processing tasks for the measurement data of each sample. In such a long-time, automatic operation, the user rarely keeps watching the system on a continuous basis; he or she usually checks only the final result of the data-processing operation by printing out a report.
When a conventional data-processing system is used in this manner, if an error has occurred in a certain data-processing step and prevented the following process to be correctly performed, the printout of the report presents only the final, erroneous result, e.g. the digit “0”. From this simple information, the user cannot identify the step in which the error has occurred. Therefore, he or she has to take the trouble of operating the data-processing system to locate the step in which the error has occurred, identify the cause of the error and solve the problem.